1. Field of the Invention
The present invention relates to optical touch, and more particularly, to an optical touch apparatus capable of receiving light signals of various directions in the display unit and reducing the imaging error of the image.
2. Description of the Prior Art
In recent years, with the continuous development of the touch image display technology, the conventional input function of the keyboard and mouse has been gradually replaced by various touch technological products. Accordingly, it is unnecessary to dispose keyboard on the electronic products or bring other input devices, so that the convenience and flexibility of the electronic products can be enhanced. In addition, since it is unnecessary to keep a region on the electronic product to dispose the keys, therefore, the size of the display monitor on the electronic product can be increased to provide the user better visual enjoyment and accuracy of the inputted data.
Please refer to FIG. 1. FIG. 1 shows a scheme diagram of the conventional optical touch apparatus 2. As shown in FIG. 1, the conventional optical touch apparatus 2 includes a display unit 20 and a light sensing module 28, wherein the light sensing module 28 includes a light path unit 22 and a light sensing unit 24. It should be noticed that the conventional light path unit 22 is an optical lens with three-dimensional spherical surface, a surface of the spherical lens is a flat surface needed to be fixed at one side of the display unit 20.
Since the conventional spherical lens is a lens with single curvature, when the spherical lens is disposed on the display unit 20, the volume of the conventional optical touch apparatus 2 should be increased, so that the cost will be increased and the beauty of space design will be also damaged.
Moreover, the imaging state of the light sensing module 28 is shown in FIG. 2A, FIG. 2A shows an enlarged diagram of the conventional light sensing module 28 in FIG. 1. It should be noticed, from y-z axis direction, it can be found that the imaging region As on the light sensing unit 24 is only a part of the maximum area of the light path unit 22, as shown in FIG. 2B. Therefore, whether the light sensing unit 24 in the light sensing module 28 is disposed on the predetermined position should be noticed. In other words, the selected position of the light sensing module 28 should be totally matched with the sensing region and background in a predetermined range, so that the functions of sensing and capturing effective image can be achieved. Therefore, it is important to select suitable light sensing module 28.
If the light sensing module 28 is disposed at one side of the display unit 20, the light sensing module 28 may be removed from its original position due to the factors such as assembly or transport vibration, then the light sensing module 28 will fail to sense the effectively readable image signals, as shown in FIG. 2C.
Therefore, the invention provides an optical touch apparatus to solve the aforementioned problems.